Protecting the contents of an envelope from tampering is a very old problem. Historical methods of producing a tamper-evident envelope used a seal imprinted into candle wax to indicate the sender sealed the envelope and no tampering had occurred en route. Since these early methods, more sophisticated methods have developed. It is well known that banks, government agencies, and businesses ship important items from one location to another. For many of these items, the shipper wants to know whether the item has been tampered with after being placed into an envelope or bag. Modern tamper-evident envelopes use a plastic or paper sheet material for the envelope, with a pre-formed seal along all but one marginal edge. After an item is placed inside the envelope, the user activates the user-activated seal, sealing the envelope.
Upon opening the tamper-evident envelope, the plastic sheet material tears, giving a clear indication of tampering. The tamper-evident envelope is then discarded. Thus, each time an object is placed in a tamper-evident envelope, a new envelope must be used.
U.S. Pat. No. 4,733,817, entitled “ENVELOPE SYSTEM WITH MULTIPLE POCKETS” discloses an envelope comprising two or more pockets. In an alternate embodiment, a perforation line separates each pocket. One adhesive containing flap is provided for each pocket to secure the contents in the pocket individually. Each pocket is used only once. The envelope system may be used multiple times if a perforation line is not present, and at least one unused pocket is sent along with the contents sealed in one of the pockets. The present invention is not limited in this regard. U.S. Pat. No. 4,733,817 is hereby incorporated by reference into the specification of the present invention.
U.S. Pat. No. 5,950,916, entitled “SECURITY ENVELOPE” discloses a reusable envelope. An elongated fold-over flap is used with a plurality of adhesive layers to permit the security envelope to be reused. The user activates an unused adhesive layer farthest from the body of the envelope to seal the envelope. Upon reaching the destination, the recipient tears the fold-over flap along a pair of perforation lines separating the activated adhesive layer and an adjacent inactivated adhesive layer. Subsequent uses of the envelope are possible by activating each remaining adhesive layer in turn. The elongated fold-over flap creates a large unsecured space. Covert entry is possible by exploiting this unsecured area. The present invention is not limited in this regard. U.S. Pat. No. 5,950,916 is hereby incorporated by reference into the specification of the present invention.
U.S. Pat. No. 6,032,854, entitled “MULTIPLE-USE SEALABLE PACKAGES” discloses an improved tamper-evident container comprising a single perforation line between a pair of user-activated seals. The perforation line creates a line of weakness between the two adhesive layers, only one of which is activated. After the first use, the container may be used again by activating the second adhesive layer. The fold-over flap creates a large unsecured space. Covert entry is possible by exploiting this unsecured area. The present invention is not limited in this regard. U.S. Pat. No. 6,032,854 is hereby incorporated by reference into the specification of the present invention.
U.S. Pat. No. 6,435,404, entitled “RETURN MAILER” discloses a reusable mailing envelope comprising a plurality of adhesives deposited on a fold-over flap and a transparent sleeve for viewing insertable mailing indicia cards. As noted above, the fold-over flap creates a large unsecured space facilitating covert entry into the interior of this unsecured area. U.S. Pat. No. 6,435,404 is hereby incorporated by reference into the specification of the present invention.
There exists a need for a multiple use tamper-evident envelope with improved resistance to tampering.